III-Nitride Semiconductor Light Emitting Device

Abstract

The present disclosure relates to a III-nitride semiconductor light-emitting device including an n-type nitride semiconductor layer, a p-type nitride semiconductor layer doped with a p-type dopant, an active layer disposed between the n-type nitride semiconductor layer and the p-type nitride semiconductor layer and including a quantum well layer to generate light by recombination of electrons and holes, and a diffusion barrier layer disposed between the quantum well layer and the p-type nitride semiconductor layer to be in contact with both layers, having a surface formed to make the interface with the p-type nitride semiconductor layer smooth, and to prevent diffusion of the p-type dopant into the quantum well layer.

1 . A III-nitride semiconductor light-emitting device, comprising:
 an n-type nitride semiconductor layer;   a p-type nitride semiconductor layer doped with a p-type dopant;   an active layer positioned between the n-type nitride semiconductor layer and the p-type nitride semiconductor layer and including a quantum well layer to generate light by recombination of electrons and holes; and   a diffusion barrier layer disposed between the quantum well layer and the p-type nitride semiconductor layer to be in contact with both the layers, having a surface formed to make the interface with the p-type nitride semiconductor layer smooth, and to prevent diffusion of the p-type dopant into the quantum well layer.   
   
   
       2 . The III-nitride semiconductor light-emitting device of  claim 1 , wherein the region of the p-type nitride semiconductor layer brought into contact with the diffusion barrier layer has a doping concentration equal to or greater than 1×10 19 /cm 3 . 
   
   
       3 . The III-nitride semiconductor light-emitting device of  claim 2 , wherein the p-type nitride semiconductor layer further comprises a region having a doping concentration lower than that of the region brought into contact with the diffusion barrier layer. 
   
   
       4 . The III-nitride semiconductor light-emitting device of  claim 1 , wherein the quantum well layer has an average doping concentration below 1×10 18 /cm 3  with respect to the p-type dopant. 
   
   
       5 . The III-nitride semiconductor light-emitting device of  claim 4 , wherein the region of the p-type nitride semiconductor layer brought into contact with the diffusion barrier layer has a doping concentration equal to or larger than 1×10 19 /cm 3 . 
   
   
       6 . The III-nitride semiconductor light-emitting device of  claim 1 , wherein the diffusion barrier layer provides a doping concentration difference of at least 50% between the p-type nitride semiconductor layer and the quantum well layer. 
   
   
       7 . The III-nitride semiconductor light-emitting device of  claim 6 , wherein the p-type dopant is magnesium. 
   
   
       8 . The III-nitride semiconductor light-emitting device of  claim 1 , wherein the diffusion barrier layer comprises gallium and indium. 
   
   
       9 . The III-nitride semiconductor light-emitting device of  claim 8 , wherein the diffusion barrier layer is made of In x Ga 1-x N, wherein x is equal to or greater than 0.01. 
   
   
       10 . The III-nitride semiconductor light-emitting device of  claim 9 , wherein the diffusion barrier layer is made of In x Ga 1-x N, wherein x is equal to or greater than 0.02. 
   
   
       11 . The III-nitride semiconductor light-emitting device of  claim 10 , wherein the diffusion barrier layer is made of In x Ga 1-x N, wherein x is equal to or greater than 0.03. 
   
   
       12 . The III-nitride semiconductor light-emitting device of  claim 11 , wherein the active layer comprises a quantum barrier layer disposed on the opposite side to the diffusion barrier layer with respect to the quantum well layer, and the quantum barrier layer comprises a smaller amount of indium than that of the diffusion barrier layer. 
   
   
       13 . The III-nitride semiconductor light-emitting device of  claim 12 , wherein the diffusion barrier layer further comprises aluminum. 
   
   
       14 . A III-nitride semiconductor light-emitting device, comprising:
 an n-type nitride semiconductor layer;   a p-type nitride semiconductor layer doped with a p-type dopant;   an active layer positioned between the n-type nitride semiconductor layer and the p-type nitride semiconductor layer and including a quantum well layer to generate light by recombination of electrons and holes;   a diffusion barrier layer positioned between the quantum well layer and the p-type nitride semiconductor layer to be in contact with both the layers, having a surface formed using gallium and indium, and preventing diffusion of the p-type dopant into the quantum well layer; and   a quantum barrier layer disposed in the active layer on the opposite side to the diffusion barrier layer with respect to the quantum well layer and containing a smaller amount of indium than that of the diffusion barrier layer.